Earlier quoted context omitted.
Insurance companies hold tremendous leverage over care providers, up to and including the power to effectively put them out of business on a whim. Care providers don't like picking fights with insurance companies.
Care providers make massively, massively more money than insurance providers.
The total industry wide profit numbers aren't relevant at all if you're running a small clinic going up against an insurance provider. Heck even if a single clinic made more money than an insurance provider, it would barely matter - the insurance providers have the power to stop covering your practice and kill it, a clinic does not have any such power over insurance providers.